(a) Field of the Invention
The present invention relates to an organic light emitting diode and, more particularly, to an organic light emitting diode that is designed being protected from moisture by being encapsulated, thereby improving luminous efficiency and life span.
(b) Description of Prior Art
Generally, an organic light emitting diode is a luminous element that emits light by an electron and an electron hole that are disappeared after being paired with each other when an electric charge is diffused on an organic electric field luminous layer provided between an electron hole diffusing electrode (a positive electrode) and an electron diffusing electrode (a negative electrode). Such an organic light emitting diode has an advantaged of being driven at a voltage lower than that required for driving an inorganic light emitting diode or a plasma display panel (PDP) by 10V.
In addition, since the organic light emitting diode is thin, light, and good in a sense of color, it has lately attracted considerable attention as a next generation flat display. The organic light emitting diode may be formed of a flexible substrate such as a plastic film.
However, since the organic light emitting diode cannot stand moisture and oxygen, its luminous efficiency and life span are steeply deteriorated when it is exposed to the air or outer moisture is infiltrated in the display. Accordingly, to protect the display from the moisture and oxygen, a metal plate such as a stainless steel is disposed on the organic light emitting diode through a well-known encapsulation process to prevent the display from directly exposed to the air.
In the encapsulation process, the metal plate and the organic light emitting diode are attached to each other by an adhesive or a UV hardening agent. However, this has a limitation in maintaining the property of the organic light emitting diode as the sealing effect cannot be sufficiently obtained at the attaching portion. Further more, the process is complicated.